Apparatus for controlling the tem



Patented Oct. 7 ,19'41 APPARATUS FOR CONTROLLING THE TEM- I PERATURE 0F EXOTHERMIC CATALYTIC REACTIONS Werner Pontow, Berlin-Fredenau, Germany, assignor to Siemens Schuckertwerke Aktiengesellschaft, Berlin-Siemensstadt, Germany, a

corporation of Germany Application April 2, 1937, Serial No. 134,689

In Germany April 3, 1 936 9 claims. (o1. :es-28s) My invention .relates to apparatus for securing an economical utilization of the catalyzer mass when effecting exothermic catalytic reactions for instance when producing benzine by the synthetic method.

The synthetic production of benzine according to the Fischer-Tropsch-method, as it is usually carried out in practice, is eiected in the manner that at rst coal or coke gas is brought into intimate contact with hydrogen or water'va-por in the presence of a catalyzer. During this process heat is continuously developed in the so-called contact oven so that a cooling apparatus must be provided Which is capable of dissipating theheat developed. Forv this reason, the contact oven is surrounded by a cooler which continuously delivers a cooling liquid. The dissipation of heat and,

chemical reaction may be reattained only if the temperature in thev contact oven is increased to a given value; If the upper limit value of the temperature is finally attained by increasing itstep.

by step, the catalyzer must then be regenerated in order that it may be utilized again. After the catalyzer has been regenerated, the processmay be repeated in the same manner; that is tosay, the process may begin again at a comparatively low temper-ature which is then, as above described, increased again step by step within certain time intervals.

However, it. has been ascertained that the catalyzer presents another peculiarity which must be therefore, the temperature may be controlled in this case in la simple manner by causing the cooler to act as an evaporating cooler and by controlling the pressure of the saturated steam produced'or by maintaining the pressure at a value corresponding to the desired temperature. To this end, it has hitherto been customary to arrange Va valve in the steam discharge conduit lof the cooling vessel or of the cooling coil, this valve being operated directly by a piston which moves against the action of a Weight and which at the Sametime is under steam pressure. f

Up to the present there has not been any rea.

sonwhatever for dispensing with this type oiy n pressure regulation. Nevertheless, it presents a drawback which manifests itself in a considerable impairment ofthe eiiiciency of the method hitherto employed. This fact, which has hitherto been overlooked and which will be hereinafter more fully dealt with, forms the basis for the present invention. According to the invention, the above-mentioned pressure regulation is effected by means of an indirectly acting governor which maintains a constant or a substantially constant rated value independently of the position of the controlled member. l

In order to further explain the invention, the behavior of the catalyzer in a benzine producer, or the like, may ilrst be dealt with.

It lies in the nature of the above-mentioned `A method or in the nature 'of the catalyzer that the chemical process takes place in the desired manner only at a predetermined temperature of the contact oven; l'This temperature must be adapted to the corresponding state of the catalyzer which acts for a certain time sutllciently catalytically at a temperature adjusted during the operation.

After this time interval has elapsed. desiredtaken'into account if an optimum economical utilization of the catalyzer mass is to beensured. It has been found that after each increase in temperature the chemical process-when the same catalyzer mass is further used-does not take place in the desired manner Within the temperature range lying below' the increased temper-ature, irrespective of whether the catalyzer has been previously utilized within vthis temperature range or not.v Consequently, if `when dealing with a freshly regenerated mass the temperature thereof is suddenly increased, for lnstance, through the in'advertence of the .attendants, to the limit temperature at which the methapparatus. must be regenerated without having been previously utilized in a proper manner.

Ifthis peculiarity of the catalyzer mass of losing its effectiveness, if the operation temperature is increased vwithout previously utilizing or sufficiently utilizing the catalytic property, is kept in mind when comparing the operation of the above-mentioned conventional apparatus for the production of benzine provided with a pressure regulating valve directly controlled by a loaded piston with the operation of an apparatus in which the pressure regulation is effected, according to the invention by an indirectly acting governor of the above-indicated type, the following basic difference becomes apparent. p

if in a convention benzine producing arrange-v "ment having its regulating valve directly controlled by means of a piston' which moves against maintained before.

the action of a weight, the contact oven is supplied with an increased quantity of gas, the amount of heat developed in the contact oven is also increased. The result is that the evaporating cooler produces steam to a greater extent, the density of steam increases as well as the steam pressure and, therefore, the temperature of the liquid in the oven also increases. Upon the increase in pressure the piston opens the valve arranged n the steam discharge conduit of the cooler to an amount which permits the increased amount of steam to be discharged and, therefore, a decrease in steam pressure results. However, with the conventional control device it is not possible to accurately reestablish the previous pressure, for as soon as the original pressure, after a regulating action, would again act on the piston, not only the piston but also the cone or disk of the control Valve would not come again into the original position owing to the rigid coupling of these parts. It therefore follows that the opened cross-section of the valve and the pressure are magnitudes which always correspond to each other, so that the pressure in the case of an increased opened cross-section of the valve which is necessary to permit the passage of the increased amount of steam, must be necessarily greaterthan the pressure which the governor This means that the abovedescribed known governor, upon an increase in load of the apparatus, increases the pressure and in a corresponding manner the temperature of the oven and the catalyzer, although no diminution of the eiectiveness of the catalyze'r has given cause for such an increase so that, as pointed out above, an operating range f temperature is lost to the process.

This does not occur if, according to the invention, an indirectly acting governorof the abovementioned type is employed for the pressure regulation. Since with this governor no direct relationship exists between the position of the controlled member and that of the controlling member, and since the latter maintains the rated value constant, a detrimental increase in temperature of the cooling agent upon fluctuations of load of the apparatus is avoided and, therefore, as above described a better utilization of the catalyzer, that is a greater efllciency of the benzine producing arrangement is ensured.

The accompanying drawing shows an apparatus for the production of benzine equipped with an indirectly acting-governor according to the invention. The left-hand portion of the drawing shows the governor proper and the right-hand portion the apparatus for producing benzine according to the so-called contact method. The contact pointer governor, illustrated, is of known type and operation.

The right-hand portion of the drawing shows the so-called contact oven. The oven contains a chamber 2 lled with a catalyzer forming an important part for carrying out the method for producing benzine. The catalyzer is amassed on a grate 3 within the chamber 2. At the bottom of the container enters a gas conduit 4, to which is supplied, for instance, coke oven gas through a conduit 5 and steam through a conduit 6. A' conduit `I connects the upper part of the chamber with an outlet conduit 9, a conduit 8 being branched on therefrom to which water gas is supplied. The conduit 9 extends to the apparatus in which the product gained is further treated in a known manner. 'I'he chamber 2 is arranged in a cooler I8. A cooling liquid, for

instance water, is continuously supplied to chamber 2 through a conduit II. The steam developing from the cooling liquid is carried off through the conduit I2 in which is arranged a control valve I3. The valve is operatively connected with a motor I4, the connection being schematically indicated by the dot and dash line |4I. The armature of the motor is designated by |42 and the field windings by |43 and |44. 42 and 43 designate two stop or limit switches which are operated by the motor I4 and the connection |4I, as will be set forth later. Motor I4 and switches 42, 43 are connected to terminals |46, some of which being connected to a supply circuit |4'I constituting an auxiliary energy source through a main switch |48 and overload protectors |49, for instance fuses.

A governor I I and two relays I5 and I6 serve to control motor I4. The operating magnet windings of the relays |5| and I6| are connected to the impulse transmitting part of the governor, hereinafter described, through terminals |51 by leads |58, |52, |62, while the contact devices of relays i5 and I6 are connected to motor I4 through terminals |56 and |48. Switches for effecting a control by hand may be inserted in the connection between .terminals |56 and I 45, as shown in the drawing.

A second auxiliary motor 22 has its, armature and its ileld winding 22| also connected to the relays I5 and I6 so as to be switched in and out together with motor I4 and to reverse its direction of rotation simultaneously with servomotor I4. The wiring system interconnecting Athe above-described parts needs no further explanation in view of its illustration in the drawing and its description of the operation set forth hereinafter. lThe impulse transmitting part of governor I 1 comprises the current carrying contact pointer I8 of a manometer, which .is connected to the conduit |2 through a conduit I 9.

and two counter-contact pointers 20 and 2| associated with pointer I8. II the steam pressure in the conduits I2 and I9 increases, the manometer pointer i8, which forms the pilot element of the control arrangement, deileots in the clockwise direction and closes whenit comes into engagement with the counter-contact pointer 2|, the circuit between leads I 52 and |58, thereby energizing relay winding I 5| and thus causing motor I4 through relay |5 to rotate in such a direction as to open the valve I8 a further amount. If the pressure in the conduit I2 decreases the pointer I8 denects in the counterclockwise direction and closes by engaging counter-contact pointer 28, the circuit between leads |62 and |58 thereby causing motor I4 through relay I8 to rotate in the opposite direction so that the valve is closed a further amoimt.

Governor I'I is provided with an automatic adjusting system of hydraulic nature, comprising two cylinders 24 and 2,8 for liquid `auch as oil, each cylinder containing a piston 24| and 25| connected toa piston rod 242 and 252 and biased by a spring 248 and 258 respectively. The

lower cylinder chambers are connected with a pump 28 by a pipe 28|. Pump 28 is connected with motor 22 as indicated by the -dot and dash line 282 so as to draw, depending upon its direction of rotation, liquid from the chamber below piston 24| in cylinder 24 and force the liquid into the chamber below piston 25| in the cylindei 25 or vice versa. The piston rods 242 and 252 are secured to a pivotally mounted lever 28 through links 244 and 254. By the movement of wise direction.

the lever 26 an arcuate gear 28 meshing with a pinion 38 is rotatedv with the aid of the links 21, 28. The counter-contact pointers 20, 2| -arcsecured to the pinion 38. The last-mentioned .parts constitute `a flexible return motion device of the governor. For adjusting or varying the rated pressure tobe maintained constant by the governor, an adjusting Y screw 3I is provided which is arranged on a rotatably mounted spindle 32. `The latter is provided with a nut not shown which when reciprocated rotates a plate 33 about a point 34. The pin 35 for the arcuate Vgear 29 is arranged in this plate. The limits within which the governor is operated may be' adjusted by a hand screw 36 by which a spacer 31 for the two counter-contact pointers 28 and by hand by means of lthe push-button switches 40 and 4I.

If switch v4I) is actuated, the motor I4 is caused to rotate in such a direction as to open the valve I3, whereas by pressing pushbutton switch 4I 4the valve I3 is closed a furtheramount. Limit 4switches 42 and 43 ensure an automatic disconnection of thernotor I4 in .case

the valve I3 reaches either end position.

The operation of the 'above-described arrangement is as follows: As long as the balance of the arrangement in operation is not disturbed, a certain constant pressure prevails in the conduit I2, the pressure depending upon a given opened cross-section of the valve'I3. The contact manometer pointer I8, the two counter-contact pointers 2|) and 2| andthe pivotally mounted lever 26 assume the position shown in the drawing. In this position the motors I4 and 22 are at rest. If now the load of the arrangement increases, that is to'say-ii a greater quantity of gas passing through the conduit 4 is forced A through the chamber 2, a greater amount of heatv is liberated, thus evaporating more cooling liquid er I8 which also moves towards its original position owing' to the-fact that the valve I3 had been opened a further amount and the pressure in the conduit I2 had been decreased. The retrogressive movement of the pointer 2| is eiected by the fact that the oil previously forced intol the space below the spring-biased piston 25| arranged in the-cylinder 25 flows through a return v-conduit 232 back into the space below thepiston Accordingly,

case the `pointer 2| does not reach, again the pointer I8. Otherwise .the pointer I8 comes into contact with the pointer 2|, whereby a circuit is closed which energizes servo-motor I4 to cause the valve I3 to open a further'amount. If the valve is not yet sufilciently opened, the process When comparing the contact manometer.

pointer I8 as an impulse transmitting member `in the container I 8. The pressurein the conduit I2 increases and the manometer pointer I8 deflects in the clockwise direction and cornes into engagement with the counter-contact pointer 2| which closes the circuit for the relay I5,

thus rotating the servo-motor I4 in such a direcf tion as-to open the valve I3. At the same time the auxiliary motory 22 is also put into operation and drivesthe oil circulating pump 23. The pump draws oil from the cylinder, 24 and forces it into the cylinder 25. In this manner the piston 24| in cylinder 24 is moved in the downward direction, whereasthe other piston moves in the upward direction. The v-lever 26 is actuated and rotates the arcuated gear 29 in the counterclockwise direction and the pinion 30, as well as pointer 2| connected to pinion 38, in the clock- 'I'hereby the circuit which had been closedby the engagement of the pointer I8 with the counter-contact pointer 2| is again broken so that both motors I4 and 22 come to rest'.- It is apparent from theabove description that there is a certain lag between the action of motor I4 and the contact opening effect of motor 22; this lag may bevery small and just suincient to operate valve I3. From this moment a retrogressive movement of the pointer 2| is inltiated so that this pointer lags behind the point-- with the displacement piston of a directly operating control device of the conventional benzinel producing arrangement, as introductorily mentioned, a striking difference becomes apparent.

In the known arrangement, a given position of the displaceable piston always corresponds, as already mentioned, to a denite position of the controlled valve.

however, such rigid relationship between the position of the controlled valve and that oi.' dis-l placeable control element does not exist. vThe pointer I8 returns at the end 'of the regulation to its original position independently of the position the valve I3 assumes. l

The invention is not limited tothe application of an evaporating cooler for cooling the contact oven nor to the control of the cooling by apressure regulator. The invention is independent of any type of cooler and may also be used in connection with a direct temperature control or alsoy with an arrangement for controlling the amount of cooling medium as the case may be. Furthermore, the invention is not limited to the above-described method for the production of 'benzine but it may also be used in such cases where similar operating conditions prevail.

an evaporative closed'c'ooling system for cooling,

said catalyzer' chamber, in combination, an 'adjustable device for regulating the temperature'in said cooling systemVa driving motor'connected with said device, an indirectly operating governor for controlling said motor, said governor having an impulse vtransmitting means containing a denectable pilot member and a deflectable follower member for producing control impulses when engaging each other, said pilot member being oper- According to the invention,

atively connected with said cooling system so as to be deflected in response to departures of said temperature from a given value, said follower member being operatively connected with said motor so as to be defiected in accordance with the adjustment of said device, and an operative connection between said two members and said driving motor for actuating said motor in accordance with said control impulses, said governor and said connection being designed to allow said member to move according to said temperature departures independently of the position of said regulating device.

2. In an apparatus for effecting exothermic catalytic reactions at a constant temperature, comprising a catalyzer chamber, means for charging and discharging said chamber with the substances to be exposed to the catalyzer, and an evaporative closed system for cooling said catalyzer chamber', the combination of an adjustable device for regulating the temperature of said cooling system, a driving motor connected with said regulating device for adjusting the latter, an auxiliary energy source connected to said motor, with a controlling governor connected with said driving arrangement, said governor having actuating means responsive to said temperature, a pilot contact connected with said actuating means, a movable counter-contact dis.. posed to be engaged by said contact, said contact and said counter-contact being electrically connected with said driving motor for actuating said driving motor upon deflections of said pilot contact, a second motor connected with said driving arrangement, means operatively connected with said second motor to cause said counter-contact to move inthe same direction as said contact and thus break-the contact between the two,` and means tending to restore the original position of rest of said counter-contact, whereby said governor by indirect action maintains said temperature constant at a given value independently of the position of said temperature regulating device.

3. An arrangement for effecting exothermic catalytic reactions at a constant temperature, particularly for synthetically producing benzine, comprising a contact oven including a catalyzer chamber, means for charging said chamber with the substances to be brought to reaction and for discharging the reaction product, and an evaporative closed fluid system for cooling said chamber, in combination with an adjustable device for regulating the temperature of said cooling system, a driving motor operatively connected with said device, an auxiliary energy source for supplying actuating energy to said motor, controlling means interposed between said energy source and said motor and designed toV cause said motor to operate said adjustable deviceiin either controlling direction in accordance with governing impulses, a governor having pilot means operatively connected with said oven arrangement so as to be responsive to said temperature, said pilot means having a movable pilot element, two cooperative elements disposed on either side of said pilot element and individually engageable by the latter in accordance with the direction of movement of said pilot element, said pilot element and said two cooperative elements being connected with said controlling means so as to eiect said governing` impulses, driving means to cause the engaged cooperative element to move in the same direction as said pilot element in correspondence with the adjustment of said device, and means for returning said cooperative element into its position of rest when said driving means have ceased operating, whereby said temperature is maintained constant independently of the position of said adjustable device.

4. In an arrangement for effecting exothermic catalytic reactions at a constant temperature, especially for synthetically producing benzine, comprising a catalyzer chamber, means for charging and discharging said chamber with the substances to be exposed to the catalyzer, and an evaporative closed fluid system for cooling said chamber, the combination of a device for regulating said cooling system, a reversible electric motor operatively connected with said device, a current source connected with said motor, and a relay set connected with said current source and said motor for controlling said motor, with a governor having a movable pilot contact, means for moving said pilot contact in correspondence with departures of the temperature in said cooling system from a given value, two countercontacts disposed on either side of said pilot contact and individually engageable by the pilot contact upon deflections of the latter from its position of rest, said pilot contact and said counter-contacts being connected `with said relay set so as to cause by their contact closure said motor to move said device in that direction which effects a temperature change causing said pilot contact to return to its position of rest, a mechanism for moving said counter-contacts in the same direction as said pilot contact and thus break the contact between them andthe pilot contact, said mechanism being operatively connected with said motor so as to be operated simultaneouslyV and according to the direction of rotation of said motor, and means for restoring the position of rest of said counter-contacts, whereby said governor effects maintenance of said temperature constant at said given value independently* of the position of said regulating device.4

5. In an arrangement for effecting exothermic catalytic reactions, comprising a catalyzer chamben-meansL for charging and discharging said chamber, and an evaporative closed cooling system in heat exchanging relation to said chamber, I

s aid system having an inlet for liquid and an outlet for vapor, the combination of a valve disposed in said outlet for regulating the vapor pressure of said system, a reversible electric motor operatively connected with said valve for adjusting the latter, a current source for energizing said motor, and a relay set connected with said current source and said motor for controlling the operation and the direction of rotation of said motor, with a governor having a pressure responsive pilotmember connected with said system, a movable pilot contact connected with said member in order/to be deflected in accordance with departures of said pressure from a given value, two' counter-contacts disposed on either side of said pilot contact and individually engageable by the pilot contact upon deflections of 'the latter from its position .of rest, said pilot contact and said counter-contactsI being connected with said relay set so as tocause by their contact closure said motor to adjust said valve in that direction which effects a. temperature change causing said pilot contact to return in its position of rest, a second motor, means connected with said second motor to cause said counter-contact to move in the same direction as said pilot contact and thus break the contact between the two, said second motor being operatively connected with said driving motor so as to be operated simultaneously and according to the direction of rotation of said driving motor, and means for restoring the position of rest of said counter-contacts, whereby said governor effects maintenance of said temperature constant at said given value independently of the position of said valve.

6. In an apparatus for effecting exothermic catalytic reactions, having an adjustable evaporative closed cooling system, for regulating the temperature of said reactions, in combination, a. motor operatively connected with said system for adjusting the l latter, an auxiliary engine source connectedv with said motor, a control arrangement disposed between said motor and said source for connecting and disconnecting said motor, a governor operatively connected with said control arrangement, said governor having a movablepilot element and at least one cooperative counter-element, said pilot element being connected with said apparatus so as to be deiiected in correspondence with departures of the temperature of said cooling system from a given value, a separate motor mechanically connected with said counter-element and electrically connected with said control arrangement so as to cause said counter-element to move in the same direction as said pilot element and thus break the contact between the two, and means tending to return said counter-element into its position of rest, whereby said temperature is maintained I constant at said given value.

7. In an apparatus for effecting `exothermic catalytic reactions at a constant temperature, having a regulatable evaporative closed cooling system for controlling the temperature of the catalytic reaction, in combination, reversible drive means for automatically adjusting said cooling system, an auxiliaryenergy source connected with said drive means, a governor for controlling said drive means, said governor having an impulse transmitter connected with said driving means and comprising two cooperative movable members, one of said members being connected with said cooling system and responsive to a condition dependent upon the temperature of said cooling systemsaid other member being connected with said means so as to be adjusted in accordance with the adjustment of said means, whereby said two members transmit control impulses to said driving means when said members are diierently deiiected from a position of rest.

8. In an apparatus for enecting -exothermic catalytic reactions, comprising a catalyzer chamber and an evaporative closed cooling system for regulating the temperature in said chamber, said cooling system having an inlet for cooling liquid, and an outlet for vapor, in combination, a pressure regulating valve arranged in said outlet, a reversible driving motor'connected with said valve, an auxiliary energy source for energizing said motor, and a governor for controlling said motor, a control connection arranged between said governor and said motor, said governor having a pressure responsive pilotmember connected with said cooling system and a movable connter-member, said pilot member and said counter-member having a given position of rest and being arranged to operate said control connection when being deflected differently from said position of rest, a s econd motor electrically connected with said first motor so as to operate in accordance with the operation of said rst motor, means connected with said second motor to cause said counter-member to move in the same direction as saidpilot member and thus break the contact between the two, and return means connected with said pilot member and tending to maintain said pilot member in. its position of rest.

9. An apparatus for effecting exothermic catalytic reactions at a constant temperature, especially for producing benzine, having an evaporative closed cooling system containing a uid cooling medium, a device for regulating the rate of iiow of said medium, in combination with an indirectly operating governor having a movable contact, elastic means tending to maintain said contact in its positionof rest, -a pilot member for deilecting said contact against the action of said elastic means, saidy pilot member being responsive to a condition dependent upon departures of said temperature from a given value, a

-movable counter-contact arranged so as to be engaged by said first contact, a drive operatively connected with said regulating device for adjusting the latter, an auxiliary energy source connected with 'said drive, an electric relay arrangement connected between said drive and said two contacts for causing said motor to adjust said device to counteract said departures, a second motor electrically connnected with said first.

motor so as to operate in accordance with the operation of said fir st motor, and means connected with said second motor to cause said counter-contact to move in the same direction as said rst contact and thus break the contact between the two.

WERNER PONTOW. 

